Switch actuating mechanism



Aug. 4, 1942. A. BLAIN SWITCH ACTUATING MECHANISM Filed May 31, 1940 2 Sheets-Sheet 1 (Ittorneg rll/////////////// E Aug. 4, 1942. A. BLAIN SWITCH AGTUATING MECHANISM Filed May 31, 1940 2 Sheets-Sheet 2 W A r i W VVI IIIII/A (Ittorneg Patented Aug. 4, 1942 SWITCH ACTUATIN G MECHANISM Albert Blain, Philadelphia, Pa., assignor to Radio Corporation of America, a corporation of Delaware Application May 31, 1940, Serial No. 338,025

4 Claims.

This invention relates to mechanisms for actuating an electric switch or other control element or device during a space of time defined by any two points or events.

It is an object of the invention to provide a mechanism capable of tripping or otherwise actuating a switch, or a series of switches, at the expiration of a measured time cycle or cycles, and one capable of being operated a number of times without affecting its intended mode of operation for any incompleted cycle.

Another and related object of the present invention is to provide a reliable, simple, compact and inexpensive device for actuating a switch at predetermined intervals.

While the invention will be described in connection with a tape cutting mechanism for a facsimile recorder, it will be understood that the disclosure in this respect is merely illustrative for purposes of explaining the inventive concept.

In the drawings,

Figure l is a plan view of a paper ribbon or tape which will be referred to in explaining one problem which the invention is designed to solve,

Figure 2 is a schematic view of a facsimile recorder including a tape cutting mechanism which is adapted to be actuated by a device constructed in accordance with the principle of the present invention,

Figure 3 is a cross-sectional view of the switch actuating device of Fig. 1,

Figure 4 is a sectional view taken on the line IV-IV of Fig. 3,

Figure 5 is a cross-sectional view of another embodiment of the invention,

Figure 6 is a sectional view taken on the line VI-VI of Fig. 5, and

Figure '7 is a detailed view in perspective of the shaft-end shown in Figs. 5 and 6.

In printing telegraph systems and in facsimile systems employing a tape or roll of paper for the recording of messages it is desirable, especially at stations handling heavy trafiic, to provide automatic means for cutting the paper into blanks of a standard size or of a size dictated by the length of the messages thereon. In such installations, the necessary presence of the paper feeding mechanism suggests that the cutting take place at a point remote from the printing point. It follows that if the cutting mechanism is to be controlled by a switch which is actuated at the end of each message, as by movement of the type bar or other printing element, such switch must be capable of remembering that the paper is to be cut at that future moment when the message thereon completes its journey from the printing point to the cutting point. Where one message immediately follows another, the switch may have to remember the stopping points of several messages.

In the case of facsimile recorders employing chemically treated paper, where it is necessary to keep the paper moving during periods when the printer is idle (so that the paper presented to the printer at any given moment will not be dried out), the situation is further complicated by the fact that the said idle periods, as well as the message periods, may be of variable duration, in which case the paper must be trimmed both at the beginning and at the end of each message. The problem in such a case is indicated in Fig. 1, wherein P designates an uncut tape containing several message areas Ml, M2, M3 of different lengths and having empty or idle spaces SI and S2, which are also of different lengths, between the several messages. The lines along which the paper is to be out are indicated at a, b, c and d.

In the telegraph receiver shown in Fig. 2 a printing device, which is exemplified by a printing bar I, prints the messages on the paper P as it is drawn over a drum 2 by means of feed rollers 3 and 4. A tape cutter which is exemplified by a fixed blade 5 and a magnetically actuated blade 6 is mounted at a convenient place remote from the printing drum 2 and out of the way of the feed rollers 3 and 4. A switch 1 controls the operation of the cutting blade 6. This switch I, in turn, is controlled by the actuating mechanism of the present invention which is shown in outline at 8, Fig. 2, and in detail in Figs. 3 and 4.

As shown in Figs. 3 and 4, the mechanism for operating the switch 1 comprises a circular case H, which will be understood to be fixed against movement, and a carrier or wheel I 2 which is mounted for rotation within the case on a central shaft or axle I 3. The wheel I3 is provided, on or adjacent its periphery with teeth or detents |2a between or in which separate actuating elements exemplified by the balls l4 are adapted to be seated. The diameter of the wheel 12, the diameter of the balls I4 and the inside diameter of the case I l are such as'to permit the balls, when seated in the detents l2a, to be carried aroundthe inner periphery of the case II and about the shaft I3 as the wheel is turned (as by the belt 9, Fig. 2) at 2. preferably uniform speed proportional to the speed of the printing drum 2 of Fig. 2.

The balls I4 are started on their course by a loading device which comprises a reservoir I5 for the balls, in the rim Ila of the case, and a plunger I6 which extends through the reservoir. The plunger I6 is biased to its outward or idle position as by means of a spring I! and is actuated by a lever arm I8 which urges the plunger inwardly against the force of its bias to seat a ball in any detent which, at the moment, is in the path of the ball.

When, as shown in Fig. 2, the invention is applied to a facsimile system, a printing telegraph, or the like, a ball I4 may be fed to the wheel I2 at the beginning and end of each message. To this end the lever arm I8 may be electrically or mechanically coupled to the printing bar I as by means of a wiping contact, I9, 20 and a relay comprising a coil 2| and an armature 22. Thus, each time the printing bar I is lowered at the beginning of a message and raised at the end of a message separate balls I4 are started on their course by the plunger I6 of the ball feed. Alternatively, the relay 2I, 22 may be actuated directly by suitable electrical impulses sent by the transmitter at the beginning and end of each message period.

The switch I of Figs. 2, 3 and 4 is mounted by any suitable or convenient means on the outer peripheral edge of the case II at a point remote from the plunger I6 and is provided with a movable arm Ia or other contact element which extends into the path of the balls through the rim Ila of the case. In the instant case the peripheral distance from the plunger I6 which starts the balls I4 on their course to the switch element 1 corresponds to the distance (in Fig. 1) from the printing point to the cutting point. Obviously, the peripheral distance between the point at which the balls start their journey and the point at which they operate the switch, or the time which each ball takes in traveling between these two points, may be as great or as small as is necessary to meet any condition of space or time. In order to permit the contact element Ia of the switch I to be entered into the path of the balls I4 or other actuating elements at any desired point, the rim Ila of the case II may be provided with a circumferential slot I lb or series of slots.

In Fig. 3, the several balls have been relatively so positioned on the carrier or wheel I2 that the paper P of Fig. 1 will be cut along the lines indicated in that figure. Thus, the ball Ma serves to actuate the cutter at point a, the ball Mb at point 12, etc. After these balls have fulfilled their function by imparting a mechanical impulse to the plunger Ia or otherwise actuating the switch 1, they are urged, as by gravity, to drop into the reservoir I5.

In the alternative embodiment of the invention shown in Figs. 5, 6 and '7, the balls which are here designated 34 travel around the shaft axis 33 with a planetary movement which is imparted to them by a carrier which in this case comprises a wheel 32 having a smooth rim 32a of a diameter calculated to urge the balls into contact with the surrounding inner surface 3Ia of the stationary case 3|. Obviously, with such planetary movement, the balls will require a much longer time to traverse a course of a given length than in the case where they are simply carried in detents on the carrier, as in the device of Figs. 3 and 4. Thus, this construction and mode of operation is of especial advantage where space is at a premium since the overall length of the ball race may be substantially less than in the first described embodiment of the invention.

In this embodiment of the invention, a portion of the inner periphery of the case is cut away to provide a reservoir 35 within which the balls idle prior to being started on the course and into which they are received upon completion of their journey. A shaft 36 having a cup shape end 36a (see Fig. '7) capable of receiving a ball, projects into the reservoir; when this cup is turned on its axis, the ball seated therein is started on its course. Since the bottom surface of the cup is presented to the reservoir 35 as the shaft is turned, the balls will be entered on their course one at a time. In this embodiment of the invention, each ball in traversing its course or orbit trips, or otherwise actuates, two switches 31 and 38, the contact elements 31a and 38a of wlr'ch project into the path of the balls from the rear surface of the case 3I. A greater or lesser number of switches may be provided where necessary or desirable. Two switches would ordinarily be provided in connection with the facsimile recorder of Fig. 2 in the event that the paper is to be cut into blanks of a standard length. In such case the first switch would be actuated by a ball at the beginning of a message and the second switch would be operated by the same ball, after a suitable interval. Any suitable means, exemplified by the screw 39 may be employed for afiixing a switch to the case at the appropriate place.

What is claimed is:

1. In a device of the character described, the combination of a planetary system including a normally idle driven element movable in an orbit, an operating station therefor disposed at a point in said orbit, and means remote from said station for rendering said element active in said orbit whereby to move said element to said station to perform a predetermined operation.

2. In a device of the character described, the combination of a planetary system including a normally idle actuating element movable in an orbit, means to mount a device to be actuated at a point adjacent said orbit, and means remote from said point for rendering said actuating element active in said orbit whereby to move said element to said station to perform a predetermined operation.

3. In a device of the character described, the combination of a planetary system including a normally idle actuating element movable in an orbit, a plurality of actuable members disposed adjacent said orbit in spaced relation to each other and in position to be successively engaged and actuated by said actuating element, and means for rendering said actuating element active in said orbit whereby to advance said actuating element along said orbit for successive engagement with said actuable members.

4. The invention as set forth in claim 3 and wherein said actuable elements are movable relative to each other along said orbit whereby their actuating interval may be varied.

ALBERT BLAIN. 

